Well sensors

ABSTRACT

A wellhead is provided having a port or ports about the external periphery of the wellhead. The center bore of each port is generally directed at a point within the wellhead having a location where a portion of a tool or an object is expected. Each port does not provide fluid access from the exterior to the interior of the wellhead and preferably has a flat bottom. Each port is fitted with a sensor and preferably the sensor contacts the bottom of the port. And ultrasonic a sensor emits an ultrasonic waveform which proceeds through the bottom of the port and a portion of the ultrasonic waveform is reflected back to the ultrasonic receiver. A comparison is then performed to compare the predicted value versus the received value to determine whether or not the expected tool or object is in place or partially in place within the wellhead.

BACKGROUND

When drilling an oil or gas well, initially a large diameter borehole is drilled. At some point it becomes necessary to case the initial large diameter borehole. A length of appropriately sized pipe is positioned in this vertical hole and cement is forced downward into the interior of the pipe and thereafter to flow upwardly in the annular area exterior of the pipe. Anchoring the pipe solidly in the earth. Thereafter, successively smaller boreholes are drilled, cased and cemented until the formation or formations are reached. In order to prepare the cased well for production, a production tubing string is run into the cased borehole. Other tubulars may be placed within the casing and not cemented.

In general, each successively smaller borehole requires a smaller diameter tubing. In order to firmly anchor a smaller diameter tubing within a larger diameter tubing a tubing hanger is installed. The tubing hanger will have a larger diameter portion to act as a shoulder that cooperates with a decreased diameter portion within the larger diameter tubular within which the tubing hanger is being fitted to act as a stop or landing for the tubing hanger.

Generally a precise fitting of the tubing hanger shoulder within the larger diameter shoulder is required due to subsequent tubulars, seals, tools, other tubing hangers, etc. that will later be landed on or fit to the current tubing hanger. Unfortunately, misalignment or improper landing of the tubing hanger onto the shoulder is an all too common occurrence. In some instances the misalignment is due to the initial preparation of the well site where the well pad is not particularly level resulting in a drilling rig that may not be normal to the surface when it begins to drill therefore the wellbore is angled as it penetrates the surface. In other instances the landing shoulder of the previous tubular may be contaminated with rock, steel shavings, or other debris so that when the subsequent tubing hanger is lowered into place the tubing hanger cannot land precisely on the shoulder. In such an event the tubing hanger may be cocked or may be high. In other instances the location of the landing shoulder may not be precisely known or the measuring instruments are imprecise. For instance some operators may use a 5 foot tally stick to tally the drill pipe over 30 or 40 feet where the intent is to locate a shoulder within half of an inch. In such a case the tubing hanger may be lowered onto what is thought to be the landing shoulder and the locking ring set but is later found to be improperly landed. In the past, tubing hangers may have had a port that penetrated the pressure vessel of the previously installed tubulars that would allow a rig worker to crawl down into the cellar underneath the wellhead and physically look into the pressure vessel as the tubing hanger was landed in order to get a visual indication of the tubing hanger being landed. However, placing a person in the cellar as tubing is being landed is precarious at best and having a penetration from the exterior into the interior of the pressure vessel is no longer desired.

Today, the only way that an operator may be certain that a tubing hanger is latched into place is to do an over pull on the tubing hanger. Unfortunately, even in over pull is not precise in that it largely depends upon the operator performing the over pull added to the possibility of damaging the rig, the wellhead or other equipment in the bore during an over pull.

SUMMARY

In an embodiment of the current invention a sensor port is formed, usually by drilling, in the bowl of the wellhead or previously placed tubular or other tool. The port is usually formed so that it has a flat bottom and does not penetrate the bowl or other pressure vessel. Generally the port is aligned such that the centerline of the port points to the landing shoulder, preferably with no occlusions or intervening spaces. Additionally, it is preferred that the bottom of the port is flat and that the ultrasonic receiver or transmitter is placed against the flat bottom port. In certain instances a second material may be placed between the bottom of the whole and the ultrasonic receiver or transmitter the second material may be a liquid or solid. It is envisioned that the sensor consists of an ultrasonic transmitter and receiver although in some instances one port may have an ultrasonic transmitter while another port has an ultrasonic receiver. The ultrasonic transmitter will transmit an ultrasonic waveform in the direction of the bowl shoulder. A portion of the ultrasonic waveform will be reflected by the interruption in the material at the edge of the bowl shoulder. The reflected ultrasonic waveform is then picked up by the ultrasonic receiver. The remainder of the ultrasonic waveform will travel on through whatever medium may be present. In some cases, in particular where the tubing hanger is improperly landed, the initial media may be air. In this case the ultrasonic waveform travels through the air and then a portion of the ultrasonic waveform will be reflected back to the ultrasonic receiver. In other instances, for instance when the tubing hanger is properly landed, immediately at the interruption in the bowl is the metal or other material of the tubing hanger. In such an instance the ultrasonic waveform enters the material of the tubing hanger and continues on until it is reflected off of the next surface. A processor having a memory and power source will then analyze the ultrasonic waveforms and compare the ultrasonic waveform returns to returns in the memory to determine whether or not the tubing hanger was landed or at least the tubing hanger shoulder was adjacent to the bowl shoulder at the point being measured.

In certain instances the ultrasonic sensor may simply give an indication, such as a light or flag, as to whether or not the tubing hanger is landed at the location being tested. In other instances multiple ultrasonic sensors may be arranged around the periphery of the wellhead. In such an instance it may be the amalgamation of all sensors to give an indication as to whether or not the tubing hanger is landed or is cocked within the wellhead. For instance in a case where you may have four sensors around the periphery of the wellhead where a 1^(st) sensor is located at 0°, a 2^(nd) sensor is located at 90°, a 3^(rd) sensor is located at 180°, and a 4^(th) sensor is located at 270° the 1^(st) sensor may indicate that the tubing hanger is on the landing shoulder within the wellhead at the 0° location. The 2^(nd) sensor may indicate that the tubing hanger is off of the landing shoulder within the wellhead by some distance X. The 3^(rd) sensor may indicate that the tubing hanger is off of the landing shoulder within the wellhead by some distance Y. The 4^(th) sensor may indicate that the tubing hanger is off of the landing shoulder within the wellhead by some distance Z. Each of the indications may then be used to determine how much and in which direction is the tubing hanger off of the shoulder.

In other instances other types of sensors may be utilized for instance strain gauges may be utilized in place of or with ultrasonic sensors. A strain gauge may be placed in the sensor port to determine whether or not a predicted load is present. If the load is either not present or differs from the predicted amount the tubing hanger may not be landed or may be set at an angle within the wellhead. If multiple strain gauges are utilized such as multiple strain gauges around the periphery of the wellhead to predicted load can be measured against the measured load to determine whether or not the tubing hanger is landed or whether the tubing hanger is set in an angle within the wellhead and at what angle it may be set.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a side cutaway view of a wellhead having a hanger landed and seated.

FIG. 2 depicts inset A from FIG. 1.

FIG. 3 is a top down view of the wellhead having sensor ports and sensors with a landed tubing hanger of FIG. 1.

FIG. 4 is a side cutaway view of a wellhead, with ultrasonic sensors, having a tubing hanger improperly landed within the wellhead.

FIG. 5 depicts inset B from FIG. 4.

FIG. 6 depicts a flowchart showing at least some of the steps that the sensor and a logic controller step through.

FIG. 7 depicts a flowchart showing at least some of the steps that the sensor and a logic controller step through in instances where multiple sensors may be used around the wellhead.

DETAILED DESCRIPTION

The description that follows includes exemplary apparatus, methods, techniques, or instruction sequences that embody techniques of the inventive subject matter. However, it is understood that the described embodiments may be practiced without these specific details. When referring to the top of the device or component top is towards the surface of the well. Side is radially offset from a component but minimally longitudinally offset.

FIGS. 1-3 depict the various pieces and assemblies of a wellhead having sensor ports and sensors with a landed tubing hanger. FIG. 1 is a side cutaway view of a wellhead 102 with ultrasonic sensors 104 and 106 having a tubing hanger 112 landed within the wellhead 102. The wellhead 102 has a 1^(st) bore 108 and a 2^(nd) bore 110. Other bores and sensors may exist around the periphery of the wellhead 102 but are not shown in FIG. 1. In some embodiments the sensors may include inductive, capacitive, magnetic, accelerometers, strain gauges, or other sensors. In the embodiment shown in FIG. 1 all the preferred embodiment uses ultrasonic sensors sensor 104 may be an ultrasonic sensor while sensor 106 could be a strain gauge. When placing a sensor such as sensor 104 within wellhead 102 a bore 108 is formed within the wellhead. Preferably a bore such as bore 108 has a bottom 114 that is flat. The bottom 114 of bore 108 is generally formed to be close, preferably within one quarter of an inch, to the element that is being observed by the sensor. As shown in FIG. 1 the bottom 114 of bore 108 is placed near circumferential shoulder 116 of wellhead 102. Tubing hanger 112 includes a matching circumferential shoulder 118 that lands on shoulder 116 in cooperates with shoulder 116 to suspend the tubing hanger 112 within the wellhead 102. As depicted in FIG. 1 the tubing hanger 112 is properly landed within wellhead 102 so that shoulders 118 of the tubing hanger 112 are flush against shoulders 116.

FIG. 2 depicts inset A from FIG. 1. As can be seen bore 108 includes a flat bottom 114 so that the matching flat bottom 116 of sensor 104 can be placed flush against the flat bottom 114. Sensor 104 may be an ultrasonic emitter or a receiver or in this case is both an ultrasonic emitter and receiver. Sensor 104 will emit an ultrasonic pulse 120 towards shoulder 116. The ultrasonic pulse 120 is then reflected back towards sensor 104 as a reflection 122. In the event that tubing hanger 112 is properly landed such that tubing hanger shoulder 118 abuts wellhead shoulder 116 then sensor 104 will see a single reflection.

FIG. 3 is a top down view of the wellhead having sensor ports and sensors with a landed tubing hanger of FIG. 1. The wellhead 102 has landed within it the tubing hanger 112. As can be seen in this view the wellhead 102 has bore 108 with sensor 104 therein and bore 110 with sensor 106 therein. Additionally, we can now see bore 109 having sensor 105 therein and bore 111 having sensor 107 therein. Each sensor will, in this instance, emit an ultrasonic pulse and will receive the echo of the emitted ultrasonic pulse. Generally, with the tubing hanger 112 landed on the shoulder 116 a single echo will be returned. In certain instances each of the sensors may be different types of sensors in that one bore may have an ultrasonic sensor placed within the bore while another bore may have a magnetic or strain gage sensor within the bore.

FIG. 4 is a side cutaway view of a wellhead 502, with ultrasonic sensors 504 and 606, having a tubing hanger 512 improperly landed within the wellhead 502. The improper landing of the tubing hanger 512 within the wellbore may be caused by debris within the wellhead 502, improper alignment of the wellhead, improper alignment of the tubing hanger, or other causes. The wellhead 502 has a 1^(st) bore 508 and a 2^(nd) bore 510. Other bores and sensors may exist around the periphery of the wellhead 502 but are not shown in FIG. 4. In some embodiments the sensors may include inductive, capacitive, magnetic, accelerometers, strain gauges, or other sensors. In the preferred embodiment in FIG. 4 the sensors are ultrasonic sensors. In other embodiments sensor 504 may be an ultrasonic sensor while sensor 506 could be a strain gauge. When placing a sensor such as sensor 504 within wellhead 502 a bore, such as bore 508 is formed within the wellhead. Preferably the bore 508 has a bottom 514 that is flat. The bottom 514 of bore 508 is generally formed to be near, preferably within one quarter of an inch, to the element that is being observed by the sensor 504. As shown in FIG. 4 the bottom 514 of bore 508 is placed near circumferential shoulder 516 of wellhead 502. Tubing hanger 512 includes a matching circumferential shoulder 518 that lands on circumferential shoulder 516 in cooperation with shoulder 516 to suspend the tubing hanger 512 within the wellhead 502.

As depicted in FIG. 4 the tubing hanger 512 is improperly landed within wellhead 502. Tubing hanger shoulder 518 is relatively flush to wellhead shoulder 517. The adjacent sensor 506 emits an ultrasonic signal 521 and receives reflection or echo 523. The single reflection 523 indicates that tubing hanger shoulder 518 is relatively flush to wellhead shoulder 517. However, due to tubing hanger 512 being improperly landed, tubing hanger shoulder 518 is held above wellhead shoulder 516. The adjacent sensor 504 emits an ultrasonic signal 525 and receives a first reflection 527 from wellhead shoulder 516 and also receives a second reflection 529. The two reflections 527 and 529 indicates that tubing hanger shoulder 518 is some distance away from wellhead shoulder 516 and the tubing hanger 512 is therefore not properly landed within wellhead 502.

FIG. 5 depicts inset B from FIG. 4. Ultrasonic sensor 504 is in place within bore 508 within wellhead 502. Wellhead 502 has a shoulder 516 near the flat bottom 514 of bore 508. The tubing hanger 512 has been improperly landed within wellhead 502 such that tubing hanger shoulder 518 is not landed on wellhead shoulder 516 leaving a void 517 between the tubing hanger 512 and the shoulder 518. Ultrasonic sensor 504 emits a pulse 525 through flat bottom 514 of bore 508 in the direction of shoulder 516. A portion of pulse 525 is reflected back towards ultrasonic sensor 504 from shoulder 516. Another portion of pulse 525 continues to travel on past shoulder 516 through void 517 where a portion of the pulse 525 is reflected by tubing hanger 512, shown here as reflection 529. In some instances pulse 525 may be reflected by shoulder 518 or may be partially reflected by debris in void 517 while another portion is reflected by the next solid object in pulse 525's path.

FIG. 6 depicts a flowchart showing at least some of the steps that the sensor and onboard logic controller and/or the sensor and a separate logic controller would go through in order to make a determination whether or not a device is landed on the shoulder or not. As depicted the sensor will emit a signal 602 and a determination will be made as to whether or not the signal was reflected back to the sensor 604. If no signal reflection is detected in the sensor repeats until a signal is detected 606. If the signal is detected then a determination is made is there a single reflection or multiple reflections 608. If only a single signal reflection is detected then the shoulder is landed and an indication will be provided to signal an operator that the shoulder is landed 610. The indication may be a light or other physical indicator on the sensor. In other instances, the indication may be given on a screen that is connected to the logic controller. If 2 or more signals are received then a determination is made as to the time delta between the 1^(st) 2 signals. If the time delta is less than the preset time delta then the 2 signals may be considered as a single signal and the tubing hanger may be considered landed with an appropriate indication given to the operator 614. If the time delta is greater than a preset then the 2 signals may be compared to a signal library 616. Provided that a comparison is found within the signal library and indication is given to the operator regarding the improper landing. 618 In some instances if there is no signal library then the logic controller is instructed to calculate the size of the void, i.e. how far off of the wellhead shoulder is the tubing hanger, by utilizing the time delta between the 2 signal reflections and the speed of the signal 620. If the calculated distance is greater than a preset value than a not landed message as well as the distance is provided on the display 622. If the calculated distance is less than the preset value than the landed indication is provided 655.

In certain instances, as depicted in FIG. 7 multiple sensors may be used around the circumference of the wellhead, such as the wellhead shown in FIG. 3. Reference points for each sensor location will be input into the logic controller 710. The logic controller may then proceed through each of the steps as indicated in FIG. 6 to provide an output, such as output 655 for each sensor location 712. If the distance as calculated for output 655 is 0.00, or at least less than a preset value, then a landed indication will be provided 714. If the distance is greater than the preset value or 0.00 then the logic controller uses the size of the wellhead and the position of each sensor around the wellhead along with the distance that the tubing hanger or other device being positioned within the head is above the respective shoulder as provided in output 655 to calculate the distance and direction of the misalignment between the tubing hanger and the wellhead 720.

While a wellhead and tubing were referenced in the description above it is understood that wellhead and tubing hanger were used only as examples and any device landing in a second device may utilize this method.

The nomenclature of leading, trailing, forward, rear, clockwise, counterclockwise, right hand, left hand, upwards, and downwards are meant only to help describe aspects of the tool that interact with other portions of the tool.

Plural instances may be provided for components, operations or structures described herein as a single instance. In general, structures and functionality presented as separate components in the exemplary configurations may be implemented as a combined structure or component. Similarly, structures and functionality presented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements may fall within the scope of the inventive subject matter. 

What is claimed is:
 1. A well sensor system comprising: a first tubular having a throughbore, wherein the throughbore has a first landing shoulder, a second tubular having a second landing shoulder, wherein the first landing shoulder and the second landing shoulder cooperate to support the second tubular within the throughbore, a bore within the first tubular and adjacent to the first landing shoulder, wherein the bore does not penetrate to the throughbore, and a sensor within the bore capable of detecting the second landing shoulder.
 2. The well sensor system of claim 1 wherein, the sensor transmits and receives an ultrasonic pulse.
 3. The well sensor system of claim 1 wherein, the sensor is magnetic.
 4. The well sensor system of claim 1 wherein, the sensor is a strain gage.
 5. A well sensor system comprising: a first tubular having a throughbore, wherein the throughbore has a first landing shoulder, a second tubular having a second landing shoulder, wherein the first landing shoulder and the second landing shoulder cooperate to support the second tubular within the throughbore, at least two bores within the first tubular and adjacent to the first landing shoulder, wherein the at least two bores do not penetrate to the throughbore, and a sensor within each of the at least two bores are capable of detecting the second landing shoulder.
 6. The well sensor system of claim 5 wherein, the sensor transmits and receives an ultrasonic pulse.
 7. The well sensor system of claim 5 wherein, each sensor within a bore is either a magnetic, ultrasonic, or strain gage sensor.
 8. The well sensor system of claim 5 wherein, the sensors is magnetic.
 9. The well sensor system of claim 5 wherein, the sensor is a strain gage
 10. The well sensor system of claim 5 wherein, the sensor within each of the at least two bores are capable of detecting the distance between the first shoulder and the second shoulder.
 11. A well sensor system comprising: a first tubular having a throughbore, wherein the throughbore has a first landing shoulder, a second tubular having a second landing shoulder, wherein the first landing shoulder and the second landing shoulder cooperate to support the second tubular within the throughbore, at least two bores within the first tubular and adjacent to the first landing shoulder, wherein the at least two bores do not penetrate to the throughbore, and a sensor within each of the at least two bores are capable of detecting the second landing shoulder; wherein, the sensor within each of the at least two bores are capable of detecting the distance between the first shoulder and the second shoulder; further wherein the signals from the sensors are provided to a logic controller.
 12. The well sensor system of claim 11 wherein, the sensor transmits and receives an ultrasonic pulse.
 13. The well sensor system of claim 11 wherein, each sensor within a bore is either a magnetic, ultrasonic, or strain gage sensor.
 14. The well sensor system of claim 11 wherein, the sensors is magnetic.
 15. The well sensor system of claim 11 wherein, the sensor is a strain gage
 16. The well sensor system of claim 11 wherein, the logic controller determines the orientation of the second tubular within the throughbore. 